The invention relates to machine tools and, more particularly but not exclusively, to a machine tool for rolling the walls of hollow cylindrical components, comprising a support for holding the workpiece and at least one pair of rolls to be pressed against the wall of the workpiece (that is to say a pair of wall thickness reducing rolls) such that one roll engages the wall of the workpiece internally and the other roll engages the wall of the workpiece externally.
A machine tool of this type is described in US patent 3,287,951. In the roll wall thickness reduction method by rolling, long tubes are produced from short thick-walled tubular blanks. In the known apparatus the tubular blank is clamped in a holder and caused to rotate. At the free end of the workpiece remote from the holder there is an axially traveling roll support which presses two pairs of rolls internally and externally against the wall of the workpiece and in the course of the rolling operation the rolls are displaced axially towards the support. An axially extending space is left between the roll support and the position at which the rolls are in engagement with the tube being rolled to accept the tube as its length increases owing to the reduction in wall thickness by rolling. However, this space is limited in the axial direction by the transverse part of the roll support so that only relatively short tubes may be produced with the known apparatus.